Adhesive tape dispensing apparatus



March 1, 1966 c. o. KILHAM 3,237,595

ADHESIVE TAPE DISPENSING APPARATUS Filed Oct. 27. 1960 5 Sheets-Sheet 1March 1, 1966 c. o. KlLHAM 3,237,595

ADHESIVE TAPE DISPENSING APPARATUS Filed Oct. 27. 1960 5 Sheets-Sheet 2March 1, 1966 c. o. KILHAM 3,237,595

ADHESIVE TAPE DISPENSING APPARATUS Filed 001;. 27. 1960 5 Sheets-Sheet 5March 1, 1966 c. o. KlLHAM 3,237,595

ADHESIVE TAPE DISPENSING APPARATUS Filed Oct. 27. 1960 5 Sheets-Sheet 4Mam}! 1966 c. o. KILHAM 3,237,595

ADHESIVE TAPE DISPENSING APPARATUS Filed Oct. 27, 1960 5 Sheets-Sheet 5220? 4 T220 200% & a] 244 I J55 42/6 19% 2,76- 5 W5 Mfor 1 ZZZ JJU Z 2m5 gay [/5 H 615 2w ia 65 54 well as for dispensing theadhesive coatedtape.

, 3,237,595 ADHESIVE TAPE DISPENSING APPARATUS Charles0."Kilham,'Beverly, Mass., assignor to United -Shoe MachineryCorporation, Boston, Mass., a corporation of'New Jersey Filed Oct. 27,1960, Ser. No. 65,525 2 Claims. (Cl. 118-42) plied, so that a needarises for avoiding the possibility of an operators burning his fingersfrom contact with heated parts of themachine, or for avoidingother'difiiculties in handling the tape with its adhesive coating as heattempts to grasp a dispensed length.

Besides the possibility of becoming burned as a length of adhesive tapedispensed by the machine of the type referred to is grasped by theoperator, a further difiiculty arises in'handling tape coated withpressure sensitive adhesive, particularly when the tape is cut intolengths as it is dispensed. In attempting to grasp a length of adhesivecoated tape having a strong tack, the tape may adhere to'the operators'fingers before he has obtained a firm grasp on it or the position of thetape isdisturbed, so that the operator will be unable to utilize it andafiix it accurately in the manner intended without loss of time inrestoring his grasp on it.

To assist the operator in grasping a dispensed length of tapewithoutdanger of burning or other difiioulty, according to an object ofthe present invention, the tape is severed from the supply along itscoated surface at a position where there are no exposed heated parts ofthe machine, so that in case of undesired adhesion of the coating on thetape to the operators fingers in grasping the tape, it is only necessaryfor the operator towithdraw his handfromthe machine, disengaging thetape from his fingers and thereafter making a new attempt, the adhesivegrip of the tape being broken by its connection with the supply untilsevered by a positive act on the part of the operator. Thus, the'difiiculty of restoring the tape within the. grasp of his fingers isminimized. To these ends a feature ofthe invention resides in apparatusfor dispensing a predetermined length of tape by advancing it across adelivery plate with its pressure sensitive coating facing away from thedelivery plate and a tape severing knife acting directly against theadhesive coated surface of the tape, in'which apparatus a control memberis provided for convenient access by the operator to actuate the knifeand the advancing means in sequence, so that the severed length of tapemay be freed readily without danger of adhesion from the delivery platebefore a new length may be advanced along the delivery plate for asubsequent operation. Such an arrangement is distinguished from that inprior machines of this type, in which each length of tape is bothadvanced and severed before it is removed. In the use of a machine inwhich the adhesive coated tape is advanced across the delivery platewith its pressure sensitive coating facing away from the plate, theoperator has no difficulty in grasping the tape forapplication' to anarticle and utilizing the adhesive coating on the tape to assist him inapplying it to the article intended. Thus, the tape may be removed fromUnited States Patent 0 Patented Mar. 1, 1966 the delivery plate, first,by pressing a finger lightly against the coating,'then, by actuating thecontrol member to sever the tape on the delivery plate from the supplyand, finally, by transferring the severed length to the article to betaped, a new length of tape then being advanced automatically after apredetermined time period without further attention by the operator.

In the preferred form of the machine in the presentinvention, the meansfor advancing the tape across the delivery'plate is actuated by powerincluding driving mechanism, having .a clutch and means driven from thedriving mechanism for holding the clutch in driving engagement while thenew length of tape is being projected across the plate and aconveniently located control member causes the knife to be actuated andthe clutch to "be engaged in proper time sequence, the knife beingactuated by the operator uponmovement of the control member in onedirection and the clutch being engaged upon movement of the controlmember in the opposite direction. In its preferred form, the controlmember consists of a yieldingly raised treadle connected for actuatingthe knife by depressing the treadle and for engaging the clutch duringrelease of the treadle.

These and other features of the invention, as hereinafter described andclaimed, will be readily apparent to those skilled in the art from aconsideration of 'thefollowing detailed specification, taken inconnection with the accompanying drawings in which:

FIG. 1 is a view in front elevation with front portions of an enclosingcasing broken away and shown in section to illustrate the underlyingmechanisms of a machine embodying the features of the present invention;

FIG. 2 is a detail view on a slightly enlarged scale illustrating themanner of handling an adhesively coated tape dispensed by the machineshown in FIG. 1;

FIG. 3 is a plan view of the machine of FIG. 1' with a cover removedfrom the casing;

FIG. 4 is a detail view in left side elevation of a portion of thecasing carrying a set of switches and pilot lights;

FIG. 5 is a detail view on an enlarged scale of a base for an adhesivereservoir with a front plate removed, as employed in the machine;

FIG. 6 is a view in right side elevation of the machine shown in FIG. 1;

' spreading roll in the reservoir base of the machine;

FIG. 8 is a plan view on an enlarged scale of a portion of the tapeafter having adhesive spread thereon;

FIG. 9 is a fragmentary sectional view of a portion of the adhesivespreading roll;

FIG. 10 is a partially sectional side view looking from the left of themachine shown in FIG. 1 with certain parts broken away and removed forclarity;

FIG. 11 is a plan view, looking along the line XI--XI, of a dispensingroll and a delivery plate shown in FIG. 10;

FIG. 12 is an enlarged detail view in front elevation of the dispensingroll and delivery plate;

FIG. 13 is a further detail and partially-sectional view in endelevation and on enlarged scale of a timing switch employed in themachine; and

FIG. 14 is a wiring diagram of the machine, indicating the manner inwhich the different parts are connected electrically.

The apparatus illiustratedin the drawings is intended for use indispensing a predetermined length of tape .coated throughout its lengthon only one side with a pressure sensitive adhesive and is provided witha delivery plate, across which the coated tape is advanced, with itspressure sensitive side facing away from the plate, so

that it does not adhere to the plate and it is unnecessary in removingthe tape from the plate to free the adhesive coating therefrom, thussimplifying the operation of transferring the tape from the plate to anarticle to be taped. Accordingly, an operator may grasp the tape with avery light force insulficient to cause adhesion to his fingers or insome instances he may press one of his fingers lightly against the tapeso that only a partial adhesion occurs. In this way the tape may betransferred along the broken line 1 of FIGS. 1 and 2 without adhesiveresistance from the plate to the article to be taped with one finger, orthe article itself may be pressed against the coated side and aftersevering the tape it may be withdrawn with the length of tape to apositon where complete and smooth adhesion to the article may beaccomplished without interference or further difliculty. In case ofimproper initial adhesion of thetape with the operators fingers or withthe article, the tape may readily be disengaged from the fingers orarticle, since the dispensed length is not severed from the supply untilthe operator so chooses. After the severed length of tape is withdrawnfrom the delivery plate, a new length is automatically advanced, so asto be ready for transfer and application to a new article.

Rather than utilize a reel of tape precoated with a continuous coatingof adhesive, the machine of the present invention is provided with aheated adhesive supply reservoir from which the adhesive is coateddirectly on the tape as it is being unwound from the reel and advancedto the delivery plate. In this way a fresh coated supply of tape isalways on hand and the tape is stripped more readily from the reelwithout the inconvenience of providing a separating layer between turnson the reel or of avoiding deterioration in the coating from lengthystorage.

Referring more particularly to FIG. 2 of the drawings, it is apparentthat if a length of adhesive tape 2 is lightly attached by itscontinuous coating 3 to an operators index finger 4 it may be applied toan article 6 in the direction of the arrows merely by brushing it acrossthe surface of 1 the article and squeezing it against the article by anoperators thumb 8 or the article may be pressed directly against thetape. The tape may then be applied smoothly by wrapping it about thearticle with a rolling action between the thumb and index finger, theadhesion of the tape with the article having sufficient tenacity whenfirst applied to enable the index finger or the article to be strippedfrom the tape during the complete application of the tape. Handling thetape by reason of light adhesion to the operators index finger is mostconveniently accomplished after the tape is dispensed from the machineand before severance takes place. Whether the advancing and severing areinitiated automatically upon removal of the length of tape or manuallywhenever a new length of tape is required, it is dispensed with itsadhesive coating exposed and preferably while the tape is stillconnected to the supply, so that improper contact of the index finger orthe article with the tape may be broken by reason of the connection ofthe length with the supply, thus assisting a new corrected contact withthe tape.

The adhesive coated tape is advanced freely without adhesive restrictionacross a stationary delivery plate, indicated at 10, mounted in ahorizontal position at one side of the machine and extending through anopening 12 (see FIG. 6) in a hinged setback door 14 at the right side ofthe machine. The door 14 is mounted for swinging movement about avertical piano hinge 16 secured to a casing 18 at the same side of themachine. The casing 18 surrounds the entire machine and is provided witha top cover plate 20 and a base plate 22. Connected to the base plate 22beneath the machine are four blocks 24 forming supporting legs for themachine, by means of which the machine may be mounted on a table top 26while providing ventilation for the heated adhesive reservoir and otheroperating parts of the machine. To secure the delivery plate to the door14, the door has 4v made fast to it, by means of screws 26 (FIGS. 6 and12), an angle piece 28 having a horizontal arm to which the deliveryplate is similarly attached by screws 30 (FIG. 3). Thus, the base 22supports the delivery plate at an accessible position for an operator.

Although the tape 2 is advanced across the delivery plate with itsadhesive coating 3 uppermost, it is possible with a metal delivery platethat particles of adhesive or the edges of the tape might adhere to thedelivery plate in such manner as to interfere with the uiformadvancement of the tape. For this reason the delivery plate 10 iscomposed of a sheet of adhesion resisting material, such aspolytetrafluorethylene (TSF-Fluorocarbon) resins, particularly of thehigh melting point thermocuring type sold under the trade name ofTeflon. It is easy then to grasp the adhesive coated tape by downwardpressure against the coating 3 on the tape and to transfer the severedlength of tape from the delivery plate to an article to which it is tobe applied.

To sever the length of tape advanced across the delivery plate from thesupply, according to the present invention the tape is acted upon by aknife 32 in the form of a blade sharpened along a lower straight edgeand arranged to engage at right angles with a cutting b ock in the formof a rectangular bar 34 formed of relatively soft material such asaluminum or brass. The bar 34 is arranged transversely of the length ofthe tape and is set into a separating block 36 having its upper surfaceand that of the bar 34 mounted substantially at the level of thedelivery plate 10 and the periphery of a dispensing roll 38 (see FIG.12), the cutting block being disposed between the dispensing roll andthe delivery plate. The dispensing roll acts to advance the coated tapeacross the delivery plate and the knife is reciprocated vertically toengage the adhesively coated surface of the tape and sever it with asingle impact against the flat surface of the bar 34, as distinguishedfrom a shearing action. In this way there is little opportunity for theadhesive to stick to the knife.

As a further means to prevent the tape severing knife from adhering tothe adhesive coat on the tape, the knife is heated to a temperatureabove that which will liquefy the adhesive, the knife being in contactwith the tape for such a brief time and a limited area that nodifficulty from deterioration of the adhesive occurs. To heat the knifeit is slidingly mounted in a heated guide 40 (FIG. 11) embracing thewidth of the knife.

The knife guide 40 is composed of heat conducting block formed with arectangular cross section of a length appreciably greater than the widthof the cutting edge on the knife, which is normally maintained in looseengage ment with the guide. Along the forward edge of the knife it isheld against the guide by an angular clip 41 secured to the guide bymeans of a screw 42. Along the rear edge of the knife it is retainedagainst the guide by a block 43 secured to the guide by a screw 44. Theguide is mounted on a swinging frame 45 mounted at its lower end on astud 46 passing through a projecting portion of the frame and throughlugs on an upstanding portion of a base projecting horizontally from theadhesive reservoir indicated at 48, in FIGS. 3, 5 and 10 which has ahorizontal adhesive storage portion.

To heat the tape severing knife guide 40 at its rearward end is bored toreceive an electrical heating cartridge 50 (see FIG. 11) of sufficientcapacity to maintain it above a temperature at which the adhesive mayadhere thereto. To mount the knife guide its rearward end is made fastto the upper surface of the swinging frame 45 in 'alinement with thepath of movement of the knife. The swinging frame 45 not only supportsthe heating guide for the knife, but it has mounted at its upper portiona shaft 52 to the forward end of which the delivery roll 38 is fixed.

To actuate the tape severing knife 32 with an impact against the tapeits upper edge is pinned within a slot u formed in a downwardlyprojecting extension of an armature 54 (FIG. slidingly mounted withinthe core of an electromagnet 56. To clear the extension of armature 54the guide 40 has a semicircular cut away area 57 (FIG. 11) alined withthe armature. The electromagnet 56 is secured to *a plate 58 spaced fromthe upper surface of the swinging frame 45 by a pair of cylindricalmetal blocks 60, best shown in FIG. 10. Passing through the plate 58 andthe blocks 60 is a pair of screws 62 (FIG. 3) threaded at their lowerends into the upper surface of the swinging frame 45. Also passingthrough a threaded opening in the plate 58 and the upper portion of theswinging frame 45 is a threaded rod 64 (FIG. 10), the lower end of whichengages a threaded opening in the lower portion of the frame 45. Theupper portion of the rod 64 carries a nut 66 which assists in preventingrotation of the rod in the plate. By means of the mounting for theelectromagnet 56 and the heating guide 40 for the knife 32 the parts arekept in alinement with each other and the knife 32 moves freely throughthe guide toward and from the cutting bar 34 to sever the adhesivecoated tape.

' The swinging frame 45- is maintained in a fixed position relatively tothe upwardly projecting portion of the base for the reservoir 48 by theengagement of the lower end of the rod 64 with the base. To retain theswinging frame at the position in which the rod 64 engages the .base ofthe reservoir, the swinging frame has protruding from its left side ahorizontal screw 68 (FIGS. 1 and 10) engaged by the upper end of atension spring 70, the lower end of which is engaged with a pin 72secured in the reservoir base.

To enable the dispensing roll 38 to engage the uncoated side of theadhesive tape frictionally with suflicient pressure to cause the tape tobe advanced across the delivery plate 10 with certainty, the coated sideof the tape is acted upon by a nonadhesive member 74 (FIG. 12). Themember 74 also is composed of Teflon (polytetrafluoroethylene) and ispressed yieldingly against the upper surface of the tape carried by thedelivery roll. For this purpose the member 74 is formed as a wedgeshaped block slotted to receive a laterally bent forward end of a lever76 so that the member may be raised to the broken line position of FIG.12 for convenience in rethreading the machine with tape. The lever 76has a central lug through which passes loosely a fulcrum screw 78 (FIG.10) having its right end engaged in a boss formed on the swinging frame45. The rearward end. of the lever 76 has an opening to receive thelower end of a tension spring 80, the upper end of which enters asimilar opening in the head of a screw 82 passing through a rearwardlyprojecting block 84 secured by a screw 86 to the upper surface of theplate 58. By rotating the screw 82 the force of the spring 80 may :beadjusted to press the Teflon member 74 into varying degrees of slidingengagement with the adhesive coated surface of the tape and withsufiicient pressure to cause the tape to engage the dispensing rollfrictionally, thus to insure advance of the tape as the roll 38 isrotated.

To insure that the adhesive coated tape will separate from thedispensing roll 38, so that the tape may be advanced properly across thedelivery plate, the dispensing roll is grooved about its periphery (FIG.11) and the block 36 is formed with a plurality of fingers projecting tothe left with their upper surfaces at the level of the delivery plate toenter the grooves in the dispensing roll. In this way the arc ofengagement of the tape is confined to 90 about the dispensing roll.

The apparatus for applying adhesive to the tape is substantially thesame as that disclosed in Patent No. 2,965,066 in which the reservoir 48is heated to a critical temperature of 350 F. The adhesive employed is acombined polyvinyl ethyl ether mixed with a styrene polymer resinwithout the use of a solvent. On account of the high viscosity of thisadhesive and the relatively high temperature to which it must be heatedto use it most efficiently, special precautions are required forpreventing the operator of the machine from burning his fingers whilehandling the dispensed tape. To reduce the likelihood of suchdifficulties the dispensing roll 38 is mounted in the swinging frame 45at a substantial distance above the point where the adhesive is appliedto the tape, thus enabling the adhesive coated tape to cool appreciablybetween the point of coating and the location of the delivery platewhere the operators fingers may be subjected to the temperature of thetape. Accordingly, the swinging frame 45 has at its lower end a pair ofspaced bearings through which passes a horizontal shaft 88 (FIGS. 1 and10) having fixed to its forward end a tape pressing roll 90, acting tomaintain the tape in contact with a spreading roll and at the rearwardend of the shaft 88 is a sprocket wheel 92 surrounded by a chain 94engaging a similar sprocket wheel 96, secured to the rearward end of theshaft 52. The arrangement is such that the dispensing roll 38 turns atthe same rate of peripheral speed as the pressing roll and itsassociated adhesive spreading roll.

As in the apparatus of the prior patent referred to, adhesive issupplied to the tape by the adhesive spreading roll, indicated herein at98,. which is disposed in an outlet opening (see FIG. 5) at the forwardside of the reservoir .base, the tape passing across the outlet openingbetween the pressing and spreading rolls 90 and 98 to apply the adhesiveto the under side of the tape at the same rate or peripheral speed asthat of the dispensing roll. The adhesive spreading roll 98 is securedto the forward end of a horizontal shaft 102 running through thereservoir base, and the shaft 102 has at its rearward end a sprocketwheel 104 surrounding which is a chain 106 for driving the shaft. Toinsure that the peripheral speeds of both the spreading roll 98 and thepressing roll 90 will be the same the two rolls are connected togetherby meshing gears 108 and 110 having the proper number of teeth thereonto produce a ratio equal to the diameters of the respective rolls. Asthe swinging frame 45 moves about the stud 46 the meshing relation ofthe gears 108 and 110 changes slightly without causing their teeth to bedisengaged. Thus, a reliable grip is maintained on the tape by the rollsat all times under the influence ofthe spring 70. Preferably, theadjustment of the threaded rod 64 prevents actual engagement of thepressing roll with the adhesive spreading roll when no tape is presentbetween them, so. that no contamination of the pressing roll with cementtakes place.

To assist in adjustment of the threaded rod 64 and to provide aconvenient handle in moving the swinging frame about its mounting stud46 while replacing the tape in the machine, the upper end of thethreaded rod has secured to it a knob 112. Also, the block member 74 maybe lifted separately from engagement with the dispensing roll 38 byrearward movement of the upper end of a pin 114 projecting from thelever 76. By lifting the block member 74 from the roll 38 a new supplyof tape may readily be applied to that roll while threading the machinewith tape.

The surface of the adhesive spreading roll 98 is knurled with acrosshatch pattern, as best shown in FIGS. 7 and 9, formed by two seriesof intersecting parallel grooves 116. The grooves 116 are of sufiicientdepth to receive appreciable amounts of adhesive from the outlet opening100 in the base of the adhesive reservoir 48. When the adhesive filledgrooves move toward the tape a similar over-all pattern of adhesive willbe applied to the tape as in FIG. 8. To regulate the amount of adhesiveon the tape, the roll has embracing one side thereof a doctor plate 118(FIG. 7) slidingly mounted in grooves running transversely of theoutlet, the doctor plate 118 being arranged for adjustment toward andfrom the knurled periphery of the roll. To prevent escape of theadhesive 7 the front end of the reservoir has secured to it a coverplate 119.

To provide a supply of uncoated tape the stud 46 has rotatably mountedat its forward end a flanged spool 120 (FIG. 11) over which the tapepasses from a supply reel 122, shown in FIGS. 1 and 3. Since the supplyof tape, indicated at 124, supported by the reel 122 is uncoatedsuccessive turns on the reel do not adhere one to another and the tapemay be withdrawn readily from the reel without requiring any additionalnonadhesive strip between successive turns to separate them as isrequired in the winding when the tape is adhesive coated.

The supply reel 122 is rotatably mounted on a spindle 126 (FIG. 3)having one end secured in an upstanding arm on a bracket 128 and theother end formed with a threaded opening to receive a retaining nut 130.The bracket 128 is fixed to the base 22 of the machine in a positionwhere the reel will be aligned with the guide spool 120.

To enable a predetermined length of adhesive coated tape to be advancedacross the delivery plate with uniform results the chain 106 (FIG. forthe applying roll 98, is actuated by driving mechanisms including anelectric motor, an electro-magnetic clutch, a switch for controlling theclutch, a cam for actuating the switch, a friction wheel for driving thecam and a conical drum driven from the roll driving mechanism andengaged along its conical surface by the friction wheel. The chain 106passes over a sprocket wheel 132 (FIG. 3) secured to a shaft 134 passingthrough a bearing in a bracket 136 and having its rearward end keyed toa driven member 138 of the electro-magnetic clutch. The driving memberof the clutch is indicated at 140 and is keyed to a collar 142 looselysurrounding the shaft 134. The collar 142 is secured to a driving shaft144 alined with the shaft 134 and mounted in bearings formed Within areduction gear 146 mounted on the frame of the electric driving motor,shown at 148. For energizing the electrical clutch an electro-magueticcore 150 having a coil 152 surrounds the shaft 134 and is disposed inmagnetic relation to the driving and driven members of the clutch.

To enable the length of tape advanced across the delivery plate 10 to beadjusted according to the requirements of the article being taped, theforward end of the shaft 134 has secured to it the conical drum shown at154, and is connected to the chain 106 of the roll driving mechanism.The drum 154 is engaged along its conical surface by the friction wheelat 156, secured to the cam, indicated at 158 (FIG. 13), both wheel andcam being rotatable loosely on a pin 160. The pin 160 is secured to avertical plate 162 carried by a horizontal slide 164 fitting within aguideway 166 made fast to the base 22 by screws 168. The slide 164 issecured in adjusted position along the guideway 166 by a clamp screw 170passing through a slot in the slide 164 and into threaded engagementwith the guideway. The guideway is arranged in parallel relation to theleft side surface of the conical drum so that during adjustment thefriction wheel is maintained in engagement with the conical surface ofthe drum. Thus, when the slide 164 is shifted rearwardly the wheel 156engages surface portions of the drum increasing in diameter and whenmoved in a forward direction the wheel engages the surface portions ofthe drum decreasing in diameter.

To actuate the clutch controlling switch the cam 158 is formed with aflat side and is engaged by a follower roll 172 rotatable on a pin 174passing through angularly bent tabs of an arm 176. The arm 176 isengaged by a tension spring 178 (FIG. 13) stretched between the arm anda screw 180 on the plate 162. The lower end of the arm 176 is rotatableon a screw 182 also secured in the plate 162. When the clutch isenergized the cam 158 forces the follower roll 172 outwardly and pressesthe arm 176 against a plunger of the clutch controlling switch,indicated at 184, mounted on the plate 162. When the The arrangement ofthe cam 158 and the follower roll 172 is such that when the slide 164 isadjusted along the drum the cam completes its rotation in a shorter orlonger time as compared to the rotation of the drum. Consequently, moreor less tape will be advanced across the delivery plate according toadjustment of the slide.

As in the machine of the Paulsen patent above referred to, the adhesivereservoir is heated by a pair of resistance cartridges illustrated inFIGS. 1, 5, and 10 at 186 and 188. The resistance cartridges 186 and 188are disposed at either side of an adhesive conducting passageway 190running horizontally between the reservoir 48 and the outlet 100. Toheat the reservoir and its base to a working temperature it is desirableto employ resistance cartridges of greater capacity than required toraise the parts to the desired temperature and to utilize thermostats toprevent difliculty from both overheating and underheating. For thesepurposes the upwardly projecting portion of the reservoir base haspassing through it a pair of thermostat cartridges 192 and 194 (FIG.10). The cartridge 192 isarranged to disconnect the motor 148 from itssource of power when the temperature of the reservoir falls below apredetermined minimum and the cartridge 194 is arranged to disconnectthe resistance cartridges 186 and 188 when the temperature of thereservoir rises above a predetermined maximum, as in the apparatus ofthe Paulsen patent.

To enable proper manual control of the apparatus of the invention thereare mounted on the left wall of the casing a motor control switch 196(see FIGS. 3 and 4), a heat control switch 198, and a double pole lineswitch 200. On the rear wall of the casing is a knife guide heat andcontrol switch 202. Also, on the left wall of the casing are a reservoirheat pilot light 204 and a minimum temperature pilot light 206.

The knife guide heat and control switch 202 is intended for openingandclosing the circuit to the knife guide heater. The control switch 202includes in its construction a thermostat 207 (FIG. 14) and a separateadjustable thermostat heating resistance 208 connected to the knifeguide heating cartridge 50. The switch 202 is provided with a manualoperator having a block acting to open the thermostatic switchregardless of the heat produced by the resistance 208. Connected througha flexible electrical cable 209 to the circuits in the casing is also anindependently movable unit in the form of a foot switch 210 arranged foractuation by a treadle member 212 (see FIGS. 1 and 3) hinged within aprotecting housing 214 biased yieldingly in a raised position by atension spring 215 (FIG. 14).

Surrounding the vertical portion of the adhesive reservoir 48 is aninsulating box 216 to protect the other apparatus within the casing fromexposure to excessive temperatures in the reservoir. Also mounted at therear of the casing is a separate outlet box 218 having a line connection220 and a clutch disconnecting switch 222, the operating handle of whichprojects from the upper surface of the outlet box. The outlet box ismounted on spacers 224 secured to the rearward wall of the casing toprotect the outlet box from heat developed in the casing.

The circuit connections for controlling the apparatus are illustratedmore particularly in FIG. 14, in which the line connection 220 consistsof a source of AC. power and is connected to the circuit through theline switch 200, a left hand conductor 226, the heat control switch 198,the resistance cartridges 186 and 188, the maximum heat thermostatcartridge 194 and a right hand conductor 228 to the line 220. The pilotlight 204 is arranged to be lighted whenever the switch 198 is closed.

To start the motor the switch 196 is closed, the circuit being completedfrom the conductor 226, through the switch 196, the minimum heatthermostat 192, a relay coil 230 and the right hand conductor 228. Ifthe temperature of the adhesive reservoir has reached the minimumrequired the thermostat 192 completes the circuit to the relay coil 230to close relay contacts 230A and 230B energizing the motor 148. When thetemperature of the reservoir reaches a maximum the thermostat cartridge194 opens the circuit to the resistance cartridges and preventsoverheating. If the temperature in the reservoir for any other reasondrops below the minimum permissible value the thermostat cartridge 192opens the circuit to the relay coil 230 and causes the motor to bedisconnected.

After threading the machine with the leading end of a tape from thesupply reel 122 the treadle 212 is depressed closing the circuit throughthe switch 210 to energize a relay coil 232. As soon as the coil 232 isenergized contacts 232A and 232B are closed. The contacts 232A establisha branch circuit from the switch 210 through a coil 234 of a time delayrelease relay having normally open contacts NO234A and normally closedcontacts NC234B. The arrangement is such that when the coil 234 isenergized the contacts NO234A are immediately closed and the contactsNC234B are immediately opened. Upon closing the contacts NO234A acircuit is completed from the left hand conductor 226 to the clutchcontrolling switch 184, contacts NO234A, the coil of the electromagnet56 and the right hand conductor 228. When the coil of the electromagnet56 is energized the knife 32 is projected against the cutting block 34to sever the measured length of tape from the supply.

The contacts 2328 are closed simultaneously with the contacts 232A andin circuit with the contacts 232B is a third relay coil 236 energizedfrom the left hand conductor 226, through the cam operated contacts 184,contacts NO234A and contacts 232B, to the coil 236 and the conductor228. Energizing the coil 236 causes contacts 236A to be closed toprepare a circuit through the coil 152 of the magnetic clutch. Thecircuit for this clutch coil, however, is held open by the contactsNC234B which are opened as a result of energizing the time delay relaycoil 234.

The clutch coil 152 is energized by direct current from a filter networkand a rectifier 238. The filter network includes resistors 240, 242, and246 connected in series between the left and right conductors 226 and228. Also connected between the resistors are a pair of filtercondensers 248, the common connection for which is to the left handconductor 226. Because the contacts NC234B are opened at the time thatcontacts 236A are closed the clutch coil 152 is not energized untilafter the time delay relay contacts NC234B are closed. This closure ofthe contacts NC234B takes place at an appreciable time after the tape issevered by the knife 32 in order to permit the operator to remove thetape out of the range of movement of a new length of tape about to beprojected across the dispensing plate 10.

To insure that the coil 236 remains energized until the time delaycontacts NC234B are restored to their closed position the relay of coil236 has a second set of contacts 236B connecting the cam operatedcontacts 184 directly with the coil 236. After the contacts 236B areclosed the only way to open the circuit to coil 236 is by disengagingthe cam operated contacts 184. This occurs as soon as the clutch coil152 is energized and the driving connections to the dispensing rolls arestarted in operation. As soon as this occurs the cam operated switch 184moves away from its uppermost contact, which connects the coil 236, andinto engagement with a lowermost contact, bridging the contacts 236A,thus continuing the energization of the clutch coil 152. The cam switch184 maintains the bridging lower contact closed until the necessarylength of tape has been dispensed. After the tape has been dispensed theswitch 184 is returned to its uppermost contact, as in FIG. 14, inpreparation for a new operation and the circuit to the clutch coil 152is broken so that the driving rolls are brought to rest.

The nature and scope of the invention having been indicated and aparticular embodiment described, what is claimed is:

1. Apparatus for dispensing a predetermined length of tape coated ononly one side with a pressure-sensitive adhesive, said apparatus beingprovided with a stationary delivery plate across which the tape movesand on which the tape is supported after being dispensed, means foradvancing the tape across the delivery plate with its coated side facingaway from the plate, a nonadhesive member for engaging the coated sideof the tape to press the uncoated side against the advancing means,driving mechanism for the tape advancing means, including a clutch andmeans driven from the driving mechanism for holding the clutch engagedwhile the length of tape is being projected across said delivery plate,and a cutting block mounted between the delivery plate and the advancingmeans at a position substantially level with the delivery plate toengage the uncoated side of the tape, in combination with a straightedged tape severing knife acting with a single impact against a flatsurface of the cutting block by first engaging the adhesive coated sideof the tape, electromagnetic means for actuating the knife and a controlmember arranged for convenient access by the operator to cause theelectromagnetic knife actuating means to be energized and thereafter toengage the clutch in sequence to project a new length of tape across thedelivery plate, the knife being actuated upon movement of the controlmember by the operator in one direction and the clutch being engagedupon movement of the control member in the opposite direction.

2. Apparatus for dispensing a predetermined length of tape coated ononly one side with a continuous coating of pressure-sensitive adhesive,said apparatus being provided with a flat stationary delivery plateacross which the tape moves and on which the tape is supported afterbeing dispensed, means comprising a dispensing roll engaging the tape atthe uncoated side opposite the adhesive for advancing the tape acrossthe delivery plate with its continuously coated side facing away fromthe plate, a nonadhesive member comprising a block of Teflon engagingthe coated side of the tape to press the uncoated side against theadvancing means, a resiliently actuated lever on which the block ofTeflon is secured for sliding engagement with the coated side of thetape, a cutting block mounted between the delivery plate and theadvancing means at a position substantially level with the deliveryplate to engage the uncoated side of the tape, a vertical adhesivesupply reservoir formed with a heated base extending laterally beyondthe vertical portion of the reservoir, and an adhesive conductingpassageway running from the reservoir horizontally through the extensionof the base and having an outlet opening at one side of the verticalportion of the reservoir, across which opening in the extension of thebase the tape is drawn by the dispensing means to coat the adhesive onthe tape, the tape being advanced across the delivery plate with theadhesive side up for enabling the adhesive to cool between the coatingoutlet and the location of the delivery plate, in combination with astraight-edged tape severing knife acting with a single impact against aflat surface of the cutting block by first engaging the adhesive coatedside of the tape.

References Cited by the Examiner UNITED STATES PATENTS 1,384,081 7/1921Mortimer 118-41 1,810,987 6/1931 Schmitt 83--171 1,987,197 1/1935Krueger et a1 11841 (Other references on following page) 8 1 1 UNITEDSTATES PATENTS Heckrnan 11841 Anderson 83203 McCain 83922 Krueger 226-96Von Stoeser 83203 Faulkner et a1 118-44 Hernpel 83203 Cefaly 83658Labine et a1 11841 Eger et a1 11842 X Paulsen 118407 Possis et a1 83-9221 2 FOREIGN PATENTS 292,685

1/1916 Germany.

5 OTHER REFERENCES Rudner: Fluorocarbons, 1958, page 13 relied on. Copyin Scientific Library. Reinhold Publishing Corp., New York.

10 MORRIS KAPLAN, Primary Examiner.

CARL W. TOMLIN, J. B. SPENCER, RICHARD'D.

, NEVIUS, CHARLES A. WILLMUTH, Examiners.

1. APPARATUS FOR DISPENSING A PREDETERMINED LENGTH OF TAPE COATED ONONLY ONE SIDE WITH A PRESSURE-SENSITIVE ADHESIVE, SAID APPARATUS BEINGPROVIDED WITH A STATIONARY DELIVERY PLATE ACROSS WHICH THE TAPE MOVESAND ON WHICH THE TAPE IS SUPPORTED AFTER BEING DISPENSED, MEANS FORADVANCING THE TAPE ACROSS THE DELIVERY PLATE WITH ITS COATED SIDE FACINGAWAY FROM THE PLATE, A NONADHESIVE MEMBER FOR ENGAGING THE COATED SIDEOF THE TAPE TO PRESS THE UNCOATED SIDE AGAINST THE ADVANCING MEANS,DRIVING MECHANISM FOR THE TAPE ADVANCING MEANS, INCLUDING A CLUTCH ANDMEANS DRIVEN FROM THE DRIVING MECHANISM FOR HOLDING THE CLUTCH ENGAGEDWHILE THE LENGTH OF TAPE IS BEING PROJECTED ACROSS SAID DELIVERY PLATE,AND A CUTTING BLOCK MOUNTED BETWEEN THE DELIVERY PLATE AND THE ADVANCINGMEANS AT A POSITION SUBSTANTIALLY LEVEL WITH THE DELIVERY PLATE TOENGAGE THE UNCOATED SIDE OF THE TAPE, IN COMBINATION WITH A STRAIGHTEDGED TAPE SEVERING KNIFE ACTING WITH A SINGLE IMPACT AGAINST A FLATSURFACE OF THE CUTTING